Effect of environmental toxins on the fish lateral line

Abstract

Fishes use their lateral line system to sense nearfield water movement associated with both abiotic and biotic sources. Given the external location of lateral line sensory organs, we hypothesized that this system would be sensitive to exposure from toxins that accumulate in the aquatic environment. The toxicant bisphenol-A (BPA), a component of many plastics, is prevalent in U.S. watersheds. We found that BPA exposure did not influence lateral line development in zebrafish, but that BPA was toxic when applied acutely to mature lateral line organs. BPA also reduced the regenerative potential of the lateral line, suggesting that BPA may affect both sensory hair cells and surrounding supporting cells. As fish in urban areas are often exposed to high levels of road pollution that enters waterways during storm events, we also examined the effect of stormwater runoff on the lateral line. In contrast to BPA, stormwater was not acutely toxic to the mature lateral line, but it had a detrimental effect on lateral line development in both zebrafish and salmonids. Collectively, our results demonstrate that aquatic pollutants can negatively impact fish mechanosensory systems, perhaps leading to decreased survival.